bentz



Patented Aug. 25,1925. 1

UNITED "STATES WILLIAM c. nnnrz, or ATLANTA, GEORGIA.

SPARK PLUG.

Application filed June 26, 1924. Serial No. 722,510.

vision of a plug which includes a spark gap, whereby the spark across the power and ground electrodes will beintensified.

To this end, the inventionaims to pro-v vide a plug which includes an intensifying spark gap constructed so that the degree of the gap will be constantly maintained, so as to insure proper operation of theplug. Another object of the invention is the provision of a spark plug of the above character which is simple in construction,readily assembled and which may be sold at a moderate cost.

With the above and other objects in View,

the invention further includes the following novel features and details of construction, to be hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings v Figure 1 is an elevation of a spark plug constructed in accordance with the invention.

Figure 2 is a sectional view of the same.

Figure 3 is adetail sectional view of the caps Figure 4 is a sectional view of the disk.

Figure 5 is a detail view of the power electrode.

Figure 6 is a bottom plan View of the cap.

Referring to the drawings in detail wherein like characters of reference denote corresponding parts, the reference character 10 indicates the core of the plug which is formed of suitable insulating material and which is mounted within a shell 11, the

latter carrying the usual ground elec trode 12.

The core 10 is provided with a. centrally arranged longitudinally disposed opening 13 which is reduced in diameter for a portion of its length as indicatedv at 14:, so as to provide a shoulder 15. Located within the opening 13 is the threaded portion 16 of a power electrode, the latter having a threaded engagement with a sleeve 17 and being provided with a reduced portion 18 which extends through the reduced portion 14 of the core opening. The portion 18of the power electrode is surrounded by a sleeve 19.

The outer end of the power electrode is spaced from the adjacent end of the core and a disk 20 extends over this end of the core and closes theopening 13. This disk is held inplace by means of a cap 21 whose edge is bent over a shoulder 22 provided upon the outerperiphery of the core. The cap 20 carries a threaded stem 23 upon whichis mounted a binding nut 2t, soas to provide a binding post for engagement with the usual conductor wire.

The disk 20 is of n'ovelfconstruction in that it is formed of Monel metal, or other suitableheat resisting metal so that the constant firing of the plug will not burn awaythe disk and thus increase the distance between said disk and the adjacent end of the power electrode and destroy the eficiency of the spark gap thus provided. Further, the disk 20 is provided with a centrally offset portion 25 which reinforces and strengthens the disk at this point, so that the portion of the disk subjected to the greatest heat will be reinforced and strengthened and tendency towarp will' be prevented with the r'esultthat the proper degree of spark gap will be constantly main-. tained.

The invention is susceptible of variouschanges in its f0rm,proportions and minor details of construction, and the right is hereclaims.

' Having described the invention what is claimed is 1. In aspark plug, a shell, an insulating corewithin the shell, said core having an opening extending longitudinally therethrough, a power electrode within the core,

the outer end of said-electrode being spaced from the adjacent end of the core, a metal disk extending over and engaging the end of the core, a cap positioned over the end of the core and engaging the disk and an offset portion extending from the disk into and closing the adjacent end of the core opening and spaced from the adjacent end of the power electrode to provide a spark lOO 2. In a spark plug, a shell an insulating core Within the shell, said core having; an

opening extending longitudinally therethrongh, a power electrode Within the core, 5 the outer end of said electrode being spaced from the adjacent end of the core, a metal disk extending over the end of the core, a

centrally located offset portion ext-ending into the core opening and spaced from the power electi'ode'to provide a spark gap and 0 means for securing the disk in position.

In testimony whereof I aflix my signature.

lVILLIAM C. RENTZ. 

